It's been already more than five years since I wrote this article (in Spanish) on autofocus and although in many areas the innovation of DSLR’s has slowed down some, autofocus systems are still making unimagined jumps.
In this article we review the 51-point system, which was introduced in late 2007 in the Nikon D3, D300 and the evolved version of which is used in the D7100, D810 and D4S (Advanced Multi-CAM 3500). more »